net.time4j.tz.model

Class DaylightSavingRule

java.lang.Object

net.time4j.tz.model.DaylightSavingRule

Direct Known Subclasses:

GregorianTimezoneRule

public abstract class DaylightSavingRule
extends java.lang.Object

Defines a yearly pattern when and how there is a switch from winter to summer time and vice versa.

This rule describes when such a switch happens. It also determines the DST-offset. For every rule instance, a ZonalTransition can be created just by indicating the appropriate year and standard offset. The change from winter to summer time and back is usually expressed by two rule instances.

Note: The term "year" denotes the year in any calendar which is not necessarily the gregorian one. Subclasses need to define the calendar type and some calendar-specific year conversions. If subclasses also want to be serializable then they have to apply the serialization proxy pattern described by Joshua Bloch.

Since:

2.2

Method Summary

Modifier and Type	Method and Description
abstract PlainDate	getDate(int year) Determines the date of time switch dependent on given year.
OffsetIndicator	getIndicator() Yields the offset indicator which must be consulted when interpreting the date and time of time switch in terms of UTC.
int	getSavings() Yields the daylight saving amount after the time switch in seconds.
PlainTime	getTimeOfDay() Determines the clock time when the switch from winter time to summer time happens or vice versa.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getDate

public abstract PlainDate getDate(int year)

Determines the date of time switch dependent on given year.

The result must be interpreted by mean of getIndicator() in order to calculate the UTC date.

Parameters:

year - reference year when a time switch happens

Returns:

calendar date of time switch

Throws:

java.lang.IllegalArgumentException - if given year does not fit to this rule

Since:

2.2

getTimeOfDay

public PlainTime getTimeOfDay()

Determines the clock time when the switch from winter time to summer time happens or vice versa.

The result must be interpreted by mean of getIndicator() in order to calculate the UTC time.

Returns:

clock time of time switch in second precision

Since:

2.2

getIndicator

public OffsetIndicator getIndicator()

Yields the offset indicator which must be consulted when interpreting the date and time of time switch in terms of UTC.

Returns:

OffsetIndicator

Since:

2.2

getSavings

public int getSavings()

Yields the daylight saving amount after the time switch in seconds.

Returns:

DST-Offset in seconds (without standard offset)

Since:

2.2